MultiTech's official mbed team.

Radio Certification

13 Apr 2018


I'm an embedded software engineer who has been asked to look at something with which I have no previous experience. I'm also not sure the MultiTech forum is the correct place to start this discussion but I'll have a go.

MultiTech highlight the certification of the mDot and xDot as long as the MultiTech LoRaWAN stack is used unaltered.

Not having to perform certification feels like a huge advantage to me. Can anyone provide some sort of arm waving overview of what certification entails?

I've looked at various LoRa modules, and the Semtech discrete parts, but haven't found anyone else claiming certification. Have I missed anything?

There are other LoRaWAN stacks, notably the LoRaWAN feature in mbed-os 5.8. The implication of MultiTech's claim is that using any other stack and any other module (or discrete devices) would require certification. Is this true?

Does the MultiTech certification hold up in practice? In other words, by the time we've put the mDot or xDot on a PCB with some other devices, like a NFC device, will we have to perform certification anyway?

Thanks, Matt

11 Dec 2018

The dots are

FCC/CE/RCM certified for use in North America, Europe & Australia

LoRa Alliance Certified ™

Preforming certification (not a certification expert) requires doing lots of tests , and paying people to certify it (lots of time and money). The dots are certified with the stack on it. Other stacks would require certification, because the behavior could be different. The certification holds up in practice as long as the stacks are unaltered.

13 Apr 2018

Hi Matt

We do take the LoRa Dot products through FCC certifications, and FCC compliance is enforced through our (LoRaWAN) firmware. Because the LoRa Dot is a transmitter, FCC has required certification tests for" intentional radiation" and "unintentional radiation". The intentional radiator testing is involved and moderately expensive. The unintentional radiation testing is not as involved and relatively inexpensive. If developing with the mDot or xDot and using the LoRaWAN compliant libraries or firmware and you also follow our recommended antenna circuitry, the "intentional radiator" FCC certification will carry through to your design. This will allow you to utilize MultiTech FCC certification on your finished device. Once you develop the Dot into your PCB you are required to retest with the FCC for unintentional radiators (FCC Part 15), however this certification is relatively inexpensive and easy to obtain also knowing it has previously passed this cert. Not having to perform the FCC intentional radiation testing is a huge advantage for our customers when looking at time to market and total cost of ownership. If you did co-locate a second transmitter in your design with a LoRa Dot, there is additional FCC co-location testing for designs with multiple transmitters. Below is a link to our certification story.

16 Apr 2018

I assume that certification limits what MultiTech can change in in the mDot/xDot library and hence wonder if there is a public road map for Multitech's library.

In particular, is support for LoRaWAN 1.1 likely to be added?

MultiTech only recommend using the specified MBed OS version which implies the Mbed OS version is not critical to certification. Do MultiTech intend to keep up with the Mbed OS version anyway, i.e. will it move to Mbed OS 5.8 sometime soon?

I'm not sure why either of these things affect our potential application, I'm just trying to gather information. :-)

Thanks, Matt

17 Apr 2018

Hi Matt,

Our next library release will target mbed OS 5.7.7. Our development library is already at 5.7.7, so you may experiment with it in the meantime. This release will not have support for LoRaWAN 1.1, but we plan to add 1.1 support in the near future.